package leecode

func repeatedCharacter(s string) (result byte) {
	hashMap := make(map[byte]int) //key 为字符 , value为出现的次数
	for index, _ := range s {
		hashMap[s[index]]++
		if hashMap[s[index]] == 2 {
			result = s[index]
			break
		}
	}
	return
}
